2023-01-05 09:44:25

by MD Danish Anwar

[permalink] [raw]
Subject: [PATCH v13 0/6] Introduce PRU remoteproc consumer API

The Programmable Real-Time Unit and Industrial Communication Subsystem
(PRU-ICSS or simply PRUSS) on various TI SoCs consists of dual 32-bit
RISC cores (Programmable Real-Time Units, or PRUs) for program execution.

There are 3 foundation components for PRUSS subsystem: the PRUSS platform
driver, the PRUSS INTC driver and the PRUSS remoteproc driver. All were
already merged and can be found under:

1) drivers/soc/ti/pruss.c
Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
2) drivers/irqchip/irq-pruss-intc.c
Documentation/devicetree/bindings/interrupt-controller/ti,pruss-intc.yaml
3) drivers/remoteproc/pru_rproc.c
Documentation/devicetree/bindings/remoteproc/ti,pru-rproc.yaml

The programmable nature of the PRUs provide flexibility to implement custom
peripheral interfaces, fast real-time responses, or specialized data handling.
Example of a PRU consumer drivers will be:
- Software UART over PRUSS
- PRU-ICSS Ethernet EMAC

In order to make usage of common PRU resources and allow the consumer drivers to
configure the PRU hardware for specific usage the PRU API is introduced.

This is the v13 of the patch series [1]. This version of the patchset
addresses the comments made on v12 [12] of the series.

Two more patch series have been posted ([2] and [3]) that depends on this
series, one has been posted to the soc/ti/ tree and another
to the networking tree. All the 3 series including this one, has been
sent as RFC [4] to get comments and to explain the dependencies.

Changes from v12 to v13 :

*) Fixed the checkpatch warning in patch 2/6 of the series.

Changes from v11 [11] to v12 :

*) Removed extra put_device() from pru_rproc_get() API as asked by Roger.
*) Removed rproc_put() call in the API __pru_rproc_get() when
rproc_get_by_phandle() returns null. Instead of that just return the error
pointer.

Changes from v10 [10] to v11 :

*) Re-ordered the patches 2/6 and 3/6 of the series as asked by Roger. Now the
2/6 patch of the series introduces the enum pruss_pru_id and the header file
<linux/pruss.h>. The patch 3/6 of the series introduces the pru_rproc_get()
and pru_rproc_put() APIS with their actua desired arguments.

Changes from v9 [9] to v10 :

*) There was compilation issue in v9 of the series because of dependencies
between 2nd and 3rd patch of the series. Fixed the dependencies in this series.
*) Added enum documentation following the kernel-doc style [13] as asked by
Roger for 3/6 patch of the series.

Changes from v8 [8] to v9 :

*) Fixed the warnings generated by running checkpatch.pl script.
*) Added Review/Ack tags.
*) Listed just the SoBs tags for all the patches as suggested by Mathieu.
*) Removed a comment for an already documented field in patch 5/6 of this series.

Changes from v7 [7] to v8 :

*) Removed get_device(&rproc->dev) from API __pru_rproc_get() in patch 2/5 of
this series as asked by Roger.
*) Replaced all the SoBs (other than mine) to Co-developed-by tags for all
the patches in this series as asked by Mathieu.
*) Added a new patch (3/6) in this series for Introduction of pruss_pru_id enum.
Previously this enum was part of patch 2/6. As asked by Roger removed this enum
(and the APIs that are using the enum) from patch 2/6 and added it in new patch.
*) Removed a comment for an already documented field in patch 2/6 of this series.
*) Changed 'pru' to 'PRU' in comment of API pru_rproc_set_firmware() as asked by
Roger.

Changes from v6 [6] to v7 :

*) Removed example section from ti,pru-consumer.yaml as the full example
included compatible property as well which is not introduced in this series
thus creating dt check binding error. Removing the example section fixes the
dt binding check error. The example section will be included in
"ti,icssg-prueth.yaml" in the next version of series [3]
*) Updated the commit message for patch 1/5 of this series to address Krzysztof's
comment.

Changes from v5 [5] to v6 :

*) Added rproc_get_by_phandle() in pru_rproc_get()
*) Provided background of Ctable in the commit messege.
*) Removed patch "" [14] (6th Patch of the v5 of this series)
as it has dependency on series [2], thus creating a cyclic dependency.

The patch [14] will be sent along with the next version of series [2].

[1] https://patchwork.kernel.org/project/linux-remoteproc/cover/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/
[3] https://lore.kernel.org/all/[email protected]/
[4] https://patchwork.kernel.org/project/linux-remoteproc/cover/[email protected]/
[5] https://lore.kernel.org/all/[email protected]/
[6] https://lore.kernel.org/all/[email protected]/
[7] https://lore.kernel.org/all/[email protected]/
[8] https://lore.kernel.org/all/[email protected]/
[9] https://lore.kernel.org/all/[email protected]/
[10] https://lore.kernel.org/all/[email protected]/
[11] https://lore.kernel.org/all/[email protected]/
[12] https://lore.kernel.org/all/[email protected]/
[13] https://www.kernel.org/doc/html/v6.0/doc-guide/kernel-doc.html#structure-union-and-enumeration-documentation
[14] https://lore.kernel.org/all/[email protected]/

Thanks and Regards,
Md Danish Anwar


MD Danish Anwar (2):
remoteproc: pru: Add enum for PRU Core Identifiers.
remoteproc: pru: Add APIs to get and put the PRU cores

Roger Quadros (1):
remoteproc: pru: Add pru_rproc_set_ctable() function

Suman Anna (2):
dt-bindings: remoteproc: Add PRU consumer bindings
remoteproc: pru: Make sysfs entries read-only for PRU client driven
boots

Tero Kristo (1):
remoteproc: pru: Configure firmware based on client setup

.../bindings/remoteproc/ti,pru-consumer.yaml | 60 +++++
drivers/remoteproc/pru_rproc.c | 230 +++++++++++++++++-
include/linux/pruss.h | 83 +++++++
3 files changed, 368 insertions(+), 5 deletions(-)
create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
create mode 100644 include/linux/pruss.h

--
2.25.1


2023-01-05 09:55:32

by MD Danish Anwar

[permalink] [raw]
Subject: [PATCH v13 3/6] remoteproc: pru: Add APIs to get and put the PRU cores

Add two new APIs, pru_rproc_get() and pru_rproc_put(), to the PRU
driver to allow client drivers to acquire and release the remoteproc
device associated with a PRU core. The PRU cores are treated as
resources with only one client owning it at a time.

The pru_rproc_get() function returns the rproc handle corresponding
to a PRU core identified by the device tree "ti,prus" property under
the client node. The pru_rproc_put() is the complementary function
to pru_rproc_get().

Signed-off-by: Suman Anna <[email protected]>
Signed-off-by: Tero Kristo <[email protected]>
Signed-off-by: Grzegorz Jaszczyk <[email protected]>
Signed-off-by: MD Danish Anwar <[email protected]>
Reviewed-by: Roger Quadros <[email protected]>
---
drivers/remoteproc/pru_rproc.c | 128 ++++++++++++++++++++++++++++++++-
include/linux/pruss.h | 30 ++++++++
2 files changed, 156 insertions(+), 2 deletions(-)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index a1a208b31846..fe4ca1584e91 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -2,12 +2,14 @@
/*
* PRU-ICSS remoteproc driver for various TI SoCs
*
- * Copyright (C) 2014-2020 Texas Instruments Incorporated - https://www.ti.com/
+ * Copyright (C) 2014-2022 Texas Instruments Incorporated - https://www.ti.com/
*
* Author(s):
* Suman Anna <[email protected]>
* Andrew F. Davis <[email protected]>
* Grzegorz Jaszczyk <[email protected]> for Texas Instruments
+ * Puranjay Mohan <[email protected]>
+ * Md Danish Anwar <[email protected]>
*/

#include <linux/bitops.h>
@@ -112,6 +114,8 @@ struct pru_private_data {
* @rproc: remoteproc pointer for this PRU core
* @data: PRU core specific data
* @mem_regions: data for each of the PRU memory regions
+ * @client_np: client device node
+ * @lock: mutex to protect client usage
* @fw_name: name of firmware image used during loading
* @mapped_irq: virtual interrupt numbers of created fw specific mapping
* @pru_interrupt_map: pointer to interrupt mapping description (firmware)
@@ -127,6 +131,8 @@ struct pru_rproc {
struct rproc *rproc;
const struct pru_private_data *data;
struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
+ struct device_node *client_np;
+ struct mutex lock;
const char *fw_name;
unsigned int *mapped_irq;
struct pru_irq_rsc *pru_interrupt_map;
@@ -147,6 +153,120 @@ void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
}

+static struct rproc *__pru_rproc_get(struct device_node *np, int index)
+{
+ struct rproc *rproc;
+ phandle rproc_phandle;
+ int ret;
+
+ ret = of_property_read_u32_index(np, "ti,prus", index, &rproc_phandle);
+ if (ret)
+ return ERR_PTR(ret);
+
+ rproc = rproc_get_by_phandle(rproc_phandle);
+ if (!rproc) {
+ ret = -EPROBE_DEFER;
+ return ERR_PTR(ret);
+ }
+
+ /* make sure it is PRU rproc */
+ if (!is_pru_rproc(rproc->dev.parent)) {
+ rproc_put(rproc);
+ return ERR_PTR(-ENODEV);
+ }
+
+ return rproc;
+}
+
+/**
+ * pru_rproc_get() - get the PRU rproc instance from a device node
+ * @np: the user/client device node
+ * @index: index to use for the ti,prus property
+ * @pru_id: optional pointer to return the PRU remoteproc processor id
+ *
+ * This function looks through a client device node's "ti,prus" property at
+ * index @index and returns the rproc handle for a valid PRU remote processor if
+ * found. The function allows only one user to own the PRU rproc resource at a
+ * time. Caller must call pru_rproc_put() when done with using the rproc, not
+ * required if the function returns a failure.
+ *
+ * When optional @pru_id pointer is passed the PRU remoteproc processor id is
+ * returned.
+ *
+ * Return: rproc handle on success, and an ERR_PTR on failure using one
+ * of the following error values
+ * -ENODEV if device is not found
+ * -EBUSY if PRU is already acquired by anyone
+ * -EPROBE_DEFER is PRU device is not probed yet
+ */
+struct rproc *pru_rproc_get(struct device_node *np, int index,
+ enum pruss_pru_id *pru_id)
+{
+ struct rproc *rproc;
+ struct pru_rproc *pru;
+ struct device *dev;
+ int ret;
+
+ rproc = __pru_rproc_get(np, index);
+ if (IS_ERR(rproc))
+ return rproc;
+
+ pru = rproc->priv;
+ dev = &rproc->dev;
+
+ mutex_lock(&pru->lock);
+
+ if (pru->client_np) {
+ mutex_unlock(&pru->lock);
+ ret = -EBUSY;
+ goto err_no_rproc_handle;
+ }
+
+ pru->client_np = np;
+
+ mutex_unlock(&pru->lock);
+
+ if (pru_id)
+ *pru_id = pru->id;
+
+ return rproc;
+
+err_no_rproc_handle:
+ rproc_put(rproc);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(pru_rproc_get);
+
+/**
+ * pru_rproc_put() - release the PRU rproc resource
+ * @rproc: the rproc resource to release
+ *
+ * Releases the PRU rproc resource and makes it available to other
+ * users.
+ */
+void pru_rproc_put(struct rproc *rproc)
+{
+ struct pru_rproc *pru;
+
+ if (IS_ERR_OR_NULL(rproc) || !is_pru_rproc(rproc->dev.parent))
+ return;
+
+ pru = rproc->priv;
+
+ mutex_lock(&pru->lock);
+
+ if (!pru->client_np) {
+ mutex_unlock(&pru->lock);
+ return;
+ }
+
+ pru->client_np = NULL;
+ mutex_unlock(&pru->lock);
+
+ rproc_put(rproc);
+}
+EXPORT_SYMBOL_GPL(pru_rproc_put);
+
static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
{
return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
@@ -817,6 +937,8 @@ static int pru_rproc_probe(struct platform_device *pdev)
pru->pruss = platform_get_drvdata(ppdev);
pru->rproc = rproc;
pru->fw_name = fw_name;
+ pru->client_np = NULL;
+ mutex_init(&pru->lock);

for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
@@ -905,7 +1027,7 @@ MODULE_DEVICE_TABLE(of, pru_rproc_match);

static struct platform_driver pru_rproc_driver = {
.driver = {
- .name = "pru-rproc",
+ .name = PRU_RPROC_DRVNAME,
.of_match_table = pru_rproc_match,
.suppress_bind_attrs = true,
},
@@ -917,5 +1039,7 @@ module_platform_driver(pru_rproc_driver);
MODULE_AUTHOR("Suman Anna <[email protected]>");
MODULE_AUTHOR("Andrew F. Davis <[email protected]>");
MODULE_AUTHOR("Grzegorz Jaszczyk <[email protected]>");
+MODULE_AUTHOR("Puranjay Mohan <[email protected]>");
+MODULE_AUTHOR("Md Danish Anwar <[email protected]>");
MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
MODULE_LICENSE("GPL v2");
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
index e94a81e97a4c..efe89c586b4b 100644
--- a/include/linux/pruss.h
+++ b/include/linux/pruss.h
@@ -28,4 +28,34 @@ enum pruss_pru_id {
PRUSS_NUM_PRUS,
};

+struct device_node;
+
+#if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
+
+struct rproc *pru_rproc_get(struct device_node *np, int index,
+ enum pruss_pru_id *pru_id);
+void pru_rproc_put(struct rproc *rproc);
+
+#else
+
+static inline struct rproc *
+pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void pru_rproc_put(struct rproc *rproc) { }
+
+#endif /* CONFIG_PRU_REMOTEPROC */
+
+static inline bool is_pru_rproc(struct device *dev)
+{
+ const char *drv_name = dev_driver_string(dev);
+
+ if (strncmp(drv_name, PRU_RPROC_DRVNAME, sizeof(PRU_RPROC_DRVNAME)))
+ return false;
+
+ return true;
+}
+
#endif /* __LINUX_PRUSS_H */
--
2.25.1